Manchester United continue to officially deny having made an offer, but various reports have noted that the Spanish midfielder has already said his goodbyes to Chelsea teammates in West London, and already has a medical evaluation arranged for Thursday with the current Premier League champs.

BBC reports say Mata’s deal at Old Trafford will be for four and a half years.

A few things to know about the big move (easily the biggest among Premier League teams thus far in the soon-to-close January transfer window):

Assuming all goes well with the medical, Mata could debut for his new club in less than a week during United’s must-win match against relegation threatened Cardiff City. That contest is Tuesday at Old Trafford.

As Joe Prince-Wright noted earlier today while keeping tabs on the fast-moving deal between the Premier League big boys, Chelsea did quite well for itself in the profit-department. Chelsea paid $38 million to Valencia two years ago. So in addition to clearing more than $20 million on the deal, they got two highly productive years from the Spanish midfielder. So that’ll certainly buy a few more practice balls or a few new flat screens for the players’ lounge.

Speaking of Spain, a main impetus behind the move from Mata’s side was getting back on the La Furia Roja radar. With so many juicy options, Spain manager Vicente del Bosque might have had a hard time selecting a player for World Cup duty who was not getting regular games. For whatever reason, Mata had fallen from grace around Stamford Bridge; he had started just 14 games this year for Jose Mourinho.

This is finally a “W” for Manchester United in the transfer sweepstakes, a much needed one after apparent, high profile swings and misses on Cesc Fabregas, Gareth Bale and Leighton Baines, to name three.

This gives Moyes’ team, struggling for traction and in danger of failing to even finish Top Four, an experienced, creative midfielder. The playmaking duties have generally fallen this year on Wayne Rooney (not his best role), Shinji Kagawa (not quite there) and Adnan Januzaj (talented, but too young for the job).